This war is not something YouTube can or in my opinion wants to win. All they want to do is make it annoying enough for non-technical people to give up and purchase premium. They know they can't win at this game. What they can do is make these changes frequent enough and annoying enough.
Simply put, even if Google hires full time staff to keep fighting this issue, at some point not serving ads becomes cheaper. On the other side of this trench we have an opensource project backed by a mob of fed up people for whom never seeing another ad is too soon. In pure fight of numbers Google is outnumbered and outgunned.
Linux is an excellent example of community effort. It's huge, well supported and develops at a pace other companies can only dream about and yet they have around 5-10k contributors. uBlock has 40k stars on GitHub alone. Not all contributors and/or developers, but this this ads problem is something that affects everyone and is universally hated by everyone and rest assured the more Google and others try to push ads the more people will awaken to fight back.